/**
 * BxSlider v4.1.2 - Fully loaded, responsive content slider
 * http://bxslider.com
 *
 * Copyright 2014, Steven Wanderski - http://stevenwanderski.com - http://bxcreative.com
 * Written while drinking Belgian ales and listening to jazz
 *
 * Released under the MIT license - http://opensource.org/licenses/MIT
 */

;(function($){

 var plugin = {};

 var defaults = {

  // GENERAL
  mode: 'horizontal',// 'horizontal', 'vertical', 'fade' 定义slider滚动的方向，有三个值可供选择
  slideSelector: '',
  infiniteLoop: true,// 无限循环 
  hideControlOnEnd: false,// 如果设置true，将会在最后一个幻灯片隐藏“next”，在最前面的幻灯片因此“prev” 
  speed: 500,// 过渡速度
  easing: null,
  slideMargin: 0,
  startSlide: 0,
  randomStart: false,
  captions: false,// 包括图像字幕。标题是来自图像的title属性
  ticker: false,
  tickerHover: false,
  adaptiveHeight: false,// 自动高度
  adaptiveHeightSpeed: 500,
  video: false,
  useCSS: true,
  preloadImages: 'visible',
  responsive: true,
  slideZIndex: 50,
  viewportClass: 'slideBox',

  // TOUCH
  touchEnabled: true,
  swipeThreshold: 50,
  oneToOneTouch: true,
  preventDefaultSwipeX: true,
  preventDefaultSwipeY: false,

  // PAGER
  pager: true,// 是否显示切换图标
  pagerType: 'full',//如果设置full，将显示1，2，3……，如果设置short，将显示1/
  pagerShortSeparator: ' / ',
  pagerSelector: null,
  buildPager: null,
  pagerCustom: null,

  // CONTROLS
  controls: false,// 是否显示“previous”和“next”按钮
  nextText: '>',
  prevText: '<',

  // AUTO
  auto: true,// 幻灯片自动滚动 
  pause: 4000,// 切换下一张速度
  autoStart: true,
  autoDirection: 'next',// 自动滚动的顺序'next', 'prev'
  autoHover: false,// 设置鼠标mouseover将会使自动滚动暂停
  autoDelay: 0,
  autoSlideForOnePage: false,

  // CAROUSEL
  minSlides: 1,
  maxSlides: 1,
  moveSlides: 0,
  slideWidth: 0,

  // CALLBACKS
  onSliderLoad: function() {},
  onSlideBefore: function() {},
  onSlideAfter: function() {},
  onSlideNext: function() {},
  onSlidePrev: function() {},
  onSliderResize: function() {}
 }

 $.fn.bxSlider = function(options){

  if(this.length == 0) return this;

  // support mutltiple elements
  if(this.length > 1){
   this.each(function(){$(this).bxSlider(options)});
   return this;
  }

  // create a namespace to be used throughout the plugin
  var slider = {};
  // set a reference to our slider element
  var el = this;
  plugin.el = this;

  /**
   * Makes slideshow responsive
   */
  // first get the original window dimens (thanks alot IE)
  var windowWidth = $(window).width();
  var windowHeight = $(window).height();



  /**
   * ===================================================================================
   * = PRIVATE FUNCTIONS
   * ===================================================================================
   */

  /**
   * Initializes namespace settings to be used throughout plugin
   */
  var init = function(){
   // merge user-supplied options with the defaults
   slider.settings = $.extend({}, defaults, options);
   // parse slideWidth setting
   slider.settings.slideWidth = parseInt(slider.settings.slideWidth);
   // store the original children
   slider.children = el.children(slider.settings.slideSelector);
   // check if actual number of slides is less than minSlides / maxSlides
   if(slider.children.length < slider.settings.minSlides) slider.settings.minSlides = slider.children.length;
   if(slider.children.length < slider.settings.maxSlides) slider.settings.maxSlides = slider.children.length;
   // if random start, set the startSlide setting to random number
   if(slider.settings.randomStart) slider.settings.startSlide = Math.floor(Math.random() * slider.children.length);
   // store active slide information
   slider.active = { index: slider.settings.startSlide }
   // store if the slider is in carousel mode (displaying / moving multiple slides)
   slider.carousel = slider.settings.minSlides > 1 || slider.settings.maxSlides > 1;
   // if carousel, force preloadImages = 'all'
   if(slider.carousel) slider.settings.preloadImages = 'all';
   // calculate the min / max width thresholds based on min / max number of slides
   // used to setup and update carousel slides dimensions
   slider.minThreshold = (slider.settings.minSlides * slider.settings.slideWidth) + ((slider.settings.minSlides - 1) * slider.settings.slideMargin);
   slider.maxThreshold = (slider.settings.maxSlides * slider.settings.slideWidth) + ((slider.settings.maxSlides - 1) * slider.settings.slideMargin);
   // store the current state of the slider (if currently animating, working is true)
   slider.working = false;
   // initialize the controls object
   slider.controls = {};
   // initialize an auto interval
   slider.interval = null;
   // determine which property to use for transitions
   slider.animProp = slider.settings.mode == 'vertical' ? 'top' : 'left';
   // determine if hardware acceleration can be used
   slider.usingCSS = slider.settings.useCSS && slider.settings.mode != 'fade' && (function(){
    // create our test div element
    var div = document.createElement('div');
    // css transition properties
    var props = ['WebkitPerspective', 'MozPerspective', 'OPerspective', 'msPerspective'];
    // test for each property
    for(var i in props){
     if(div.style[props[i]] !== undefined){
      slider.cssPrefix = props[i].replace('Perspective', '').toLowerCase();
      slider.animProp = '-' + slider.cssPrefix + '-transform';
      return true;
     }
    }
    return false;
   }());
   // if vertical mode always make maxSlides and minSlides equal
   if(slider.settings.mode == 'vertical') slider.settings.maxSlides = slider.settings.minSlides;
   // save original style data
   el.data("origStyle", el.attr("style"));
   el.children(slider.settings.slideSelector).each(function() {
     $(this).data("origStyle", $(this).attr("style"));
   });
   // perform all DOM / CSS modifications
   setup();
  }

  /**
   * Performs all DOM and CSS modifications
   */
  var setup = function(){
   // wrap el in a wrapper
   el.wrap('<div class="' + slider.settings.viewportClass + '"></div>');
   // store a namspace reference to .bx-viewport
   slider.viewport = el.parent();
   // add a loading div to display while images are loading
   slider.loader = $('<div class="slideLoading" />');
   slider.viewport.prepend(slider.loader);
   // set el to a massive width, to hold any needed slides
   // also strip any margin and padding from el
   el.css({
    width: slider.settings.mode == 'horizontal' ? (slider.children.length * 100 + 215) + '%' : 'auto',
    position: 'relative'
   });
   // if using CSS, add the easing property
   if(slider.usingCSS && slider.settings.easing){
    el.css('-' + slider.cssPrefix + '-transition-timing-function', slider.settings.easing);
   // if not using CSS and no easing value was supplied, use the default JS animation easing (swing)
   }else if(!slider.settings.easing){
    slider.settings.easing = 'swing';
   }
   var slidesShowing = getNumberSlidesShowing();
   // make modifications to the viewport (.bx-viewport)
   slider.viewport.css({
    width: '100%',
    overflow: 'hidden',
    position: 'relative'
   });
   slider.viewport.parent().css({
    maxWidth: getViewportMaxWidth()
   });
   // make modification to the wrapper (.bx-wrapper)
   if(!slider.settings.pager) {
    slider.viewport.parent().css({
    margin: '0 auto 0px'
    });
   }
   // apply css to all slider children
   slider.children.css({
    'float': slider.settings.mode == 'horizontal' ? 'left' : 'none',
    listStyle: 'none',
    position: 'relative'
   });
   // apply the calculated width after the float is applied to prevent scrollbar interference
   slider.children.css('width', getSlideWidth());
   // if slideMargin is supplied, add the css
   if(slider.settings.mode == 'horizontal' && slider.settings.slideMargin > 0) slider.children.css('marginRight', slider.settings.slideMargin);
   if(slider.settings.mode == 'vertical' && slider.settings.slideMargin > 0) slider.children.css('marginBottom', slider.settings.slideMargin);
   // if "fade" mode, add positioning and z-index CSS
   if(slider.settings.mode == 'fade'){
    slider.children.css({
     position: 'absolute',
     zIndex: 0,
     display: 'none'
    });
    // prepare the z-index on the showing element
    slider.children.eq(slider.settings.startSlide).css({zIndex: slider.settings.slideZIndex, display: 'block'});
   }
   // create an element to contain all slider controls (pager, start / stop, etc)
   slider.controls.el = $('<div class="controlBase" />');
   // if captions are requested, add them
   if(slider.settings.captions) appendCaptions();
   // check if startSlide is last slide
   slider.active.last = slider.settings.startSlide == getPagerQty() - 1;
   // if video is true, set up the fitVids plugin
   if(slider.settings.video) el.fitVids();
   // set the default preload selector (visible)
   var preloadSelector = slider.children.eq(slider.settings.startSlide);
   if (slider.settings.preloadImages == "all") preloadSelector = slider.children;
   // only check for control addition if not in "ticker" mode
   if(!slider.settings.ticker){
    // if pager is requested, add it
    if(slider.settings.pager) appendPager();
    // if controls are requested, add them
    if(slider.settings.controls) appendControls();
    // if any control option is requested, add the controls wrapper
    if(slider.settings.controls || slider.settings.pager) slider.viewport.after(slider.controls.el);
   // if ticker mode, do not allow a pager
   }else{
    slider.settings.pager = false;
   }
   // preload all images, then perform final DOM / CSS modifications that depend on images being loaded
   loadElements(preloadSelector, start);
  }

  var loadElements = function(selector, callback){
   var total = selector.find('img, iframe').length;
   if (total == 0){
    callback();
    return;
   }
   var count = 0;
   selector.find('img, iframe').each(function(){
    $(this).one('load', function() {
      if(++count == total) callback();
    }).each(function() {
      if(this.complete) $(this).load();
    });
   });
  }

  /**
   * Start the slider
   */
  var start = function(){
   // if infinite loop, prepare additional slides
   if(slider.settings.infiniteLoop && slider.settings.mode != 'fade' && !slider.settings.ticker){
    var slice = slider.settings.mode == 'vertical' ? slider.settings.minSlides : slider.settings.maxSlides;
    var sliceAppend = slider.children.slice(0, slice).clone().addClass('bx-clone');
    var slicePrepend = slider.children.slice(-slice).clone().addClass('bx-clone');
    el.append(sliceAppend).prepend(slicePrepend);
   }
   // remove the loading DOM element
   slider.loader.remove();
   // set the left / top position of "el"
   setSlidePosition();
   // if "vertical" mode, always use adaptiveHeight to prevent odd behavior
   if (slider.settings.mode == 'vertical') slider.settings.adaptiveHeight = true;
   // set the viewport height
   slider.viewport.height(getViewportHeight());
   // make sure everything is positioned just right (same as a window resize)
   el.redrawSlider();
   // onSliderLoad callback
   slider.settings.onSliderLoad(slider.active.index);
   // slider has been fully initialized
   slider.initialized = true;
   // bind the resize call to the window
   if (slider.settings.responsive) $(window).bind('resize', resizeWindow);
   // if auto is true and has more than 1 page, start the show
   if (slider.settings.auto && slider.settings.autoStart && (getPagerQty() > 1 || slider.settings.autoSlideForOnePage)) initAuto();
   // if ticker is true, start the ticker
   if (slider.settings.ticker) initTicker();
   // if pager is requested, make the appropriate pager link active
   if (slider.settings.pager) updatePagerActive(slider.settings.startSlide);
   // check for any updates to the controls (like hideControlOnEnd updates)
   if (slider.settings.controls) updateDirectionControls();
   // if touchEnabled is true, setup the touch events
   if (slider.settings.touchEnabled && !slider.settings.ticker) initTouch();
  }

  /**
   * Returns the calculated height of the viewport, used to determine either adaptiveHeight or the maxHeight value
   */
  var getViewportHeight = function(){
   var height = 0;
   // first determine which children (slides) should be used in our height calculation
   var children = $();
   // if mode is not "vertical" and adaptiveHeight is false, include all children
   if(slider.settings.mode != 'vertical' && !slider.settings.adaptiveHeight){
    children = slider.children;
   }else{
    // if not carousel, return the single active child
    if(!slider.carousel){
     children = slider.children.eq(slider.active.index);
    // if carousel, return a slice of children
    }else{
     // get the individual slide index
     var currentIndex = slider.settings.moveSlides == 1 ? slider.active.index : slider.active.index * getMoveBy();
     // add the current slide to the children
     children = slider.children.eq(currentIndex);
     // cycle through the remaining "showing" slides
     for (i = 1; i <= slider.settings.maxSlides - 1; i++){
      // if looped back to the start
      if(currentIndex + i >= slider.children.length){
       children = children.add(slider.children.eq(i - 1));
      }else{
       children = children.add(slider.children.eq(currentIndex + i));
      }
     }
    }
   }
   // if "vertical" mode, calculate the sum of the heights of the children
   if(slider.settings.mode == 'vertical'){
    children.each(function(index) {
      height += $(this).outerHeight();
    });
    // add user-supplied margins
    if(slider.settings.slideMargin > 0){
     height += slider.settings.slideMargin * (slider.settings.minSlides - 1);
    }
   // if not "vertical" mode, calculate the max height of the children
   }else{
    height = Math.max.apply(Math, children.map(function(){
     return $(this).outerHeight(false);
    }).get());
   }

   if(slider.viewport.css('box-sizing') == 'border-box'){
    height += parseFloat(slider.viewport.css('padding-top')) + parseFloat(slider.viewport.css('padding-bottom')) +
       parseFloat(slider.viewport.css('border-top-width')) + parseFloat(slider.viewport.css('border-bottom-width'));
   }else if(slider.viewport.css('box-sizing') == 'padding-box'){
    height += parseFloat(slider.viewport.css('padding-top')) + parseFloat(slider.viewport.css('padding-bottom'));
   }

   return height;
  }

  /**
   * Returns the calculated width to be used for the outer wrapper / viewport
   */
  var getViewportMaxWidth = function(){
   var width = '100%';
   if(slider.settings.slideWidth > 0){
    if(slider.settings.mode == 'horizontal'){
     width = (slider.settings.maxSlides * slider.settings.slideWidth) + ((slider.settings.maxSlides - 1) * slider.settings.slideMargin);
    }else{
     width = slider.settings.slideWidth;
    }
   }
   return width;
  }

  /**
   * Returns the calculated width to be applied to each slide
   */
  var getSlideWidth = function(){
   // start with any user-supplied slide width
   var newElWidth = slider.settings.slideWidth;
   // get the current viewport width
   var wrapWidth = slider.viewport.width();
   // if slide width was not supplied, or is larger than the viewport use the viewport width
   if(slider.settings.slideWidth == 0 ||
    (slider.settings.slideWidth > wrapWidth && !slider.carousel) ||
    slider.settings.mode == 'vertical'){
    newElWidth = wrapWidth;
   // if carousel, use the thresholds to determine the width
   }else if(slider.settings.maxSlides > 1 && slider.settings.mode == 'horizontal'){
    if(wrapWidth > slider.maxThreshold){
     // newElWidth = (wrapWidth - (slider.settings.slideMargin * (slider.settings.maxSlides - 1))) / slider.settings.maxSlides;
    }else if(wrapWidth < slider.minThreshold){
     newElWidth = (wrapWidth - (slider.settings.slideMargin * (slider.settings.minSlides - 1))) / slider.settings.minSlides;
    }
   }
   return newElWidth;
  }

  /**
   * Returns the number of slides currently visible in the viewport (includes partially visible slides)
   */
  var getNumberSlidesShowing = function(){
   var slidesShowing = 1;
   if(slider.settings.mode == 'horizontal' && slider.settings.slideWidth > 0){
    // if viewport is smaller than minThreshold, return minSlides
    if(slider.viewport.width() < slider.minThreshold){
     slidesShowing = slider.settings.minSlides;
    // if viewport is larger than minThreshold, return maxSlides
    }else if(slider.viewport.width() > slider.maxThreshold){
     slidesShowing = slider.settings.maxSlides;
    // if viewport is between min / max thresholds, divide viewport width by first child width
    }else{
     var childWidth = slider.children.first().width() + slider.settings.slideMargin;
     slidesShowing = Math.floor((slider.viewport.width() +
      slider.settings.slideMargin) / childWidth);
    }
   // if "vertical" mode, slides showing will always be minSlides
   }else if(slider.settings.mode == 'vertical'){
    slidesShowing = slider.settings.minSlides;
   }
   return slidesShowing;
  }

  /**
   * Returns the number of pages (one full viewport of slides is one "page")
   */
  var getPagerQty = function(){
   var pagerQty = 0;
   // if moveSlides is specified by the user
   if(slider.settings.moveSlides > 0){
    if(slider.settings.infiniteLoop){
     pagerQty = Math.ceil(slider.children.length / getMoveBy());
    }else{
     // use a while loop to determine pages
     var breakPoint = 0;
     var counter = 0
     // when breakpoint goes above children length, counter is the number of pages
     while (breakPoint < slider.children.length){
      ++pagerQty;
      breakPoint = counter + getNumberSlidesShowing();
      counter += slider.settings.moveSlides <= getNumberSlidesShowing() ? slider.settings.moveSlides : getNumberSlidesShowing();
     }
    }
   // if moveSlides is 0 (auto) divide children length by sides showing, then round up
   }else{
    pagerQty = Math.ceil(slider.children.length / getNumberSlidesShowing());
   }
   return pagerQty;
  }

  /**
   * Returns the number of indivual slides by which to shift the slider
   */
  var getMoveBy = function(){
   // if moveSlides was set by the user and moveSlides is less than number of slides showing
   if(slider.settings.moveSlides > 0 && slider.settings.moveSlides <= getNumberSlidesShowing()){
    return slider.settings.moveSlides;
   }
   // if moveSlides is 0 (auto)
   return getNumberSlidesShowing();
  }

  /**
   * Sets the slider's (el) left or top position
   */
  var setSlidePosition = function(){
   // if last slide, not infinite loop, and number of children is larger than specified maxSlides
   if(slider.children.length > slider.settings.maxSlides && slider.active.last && !slider.settings.infiniteLoop){
    if (slider.settings.mode == 'horizontal'){
     // get the last child's position
     var lastChild = slider.children.last();
     var position = lastChild.position();
     // set the left position
     setPositionProperty(-(position.left - (slider.viewport.width() - lastChild.outerWidth())), 'reset', 0);
    }else if(slider.settings.mode == 'vertical'){
     // get the last showing index's position
     var lastShowingIndex = slider.children.length - slider.settings.minSlides;
     var position = slider.children.eq(lastShowingIndex).position();
     // set the top position
     setPositionProperty(-position.top, 'reset', 0);
    }
   // if not last slide
   }else{
    // get the position of the first showing slide
    var position = slider.children.eq(slider.active.index * getMoveBy()).position();
    // check for last slide
    if (slider.active.index == getPagerQty() - 1) slider.active.last = true;
    // set the repective position
    if (position != undefined){
     if (slider.settings.mode == 'horizontal') setPositionProperty(-position.left, 'reset', 0);
     else if (slider.settings.mode == 'vertical') setPositionProperty(-position.top, 'reset', 0);
    }
   }
  }

  /**
   * Sets the el's animating property position (which in turn will sometimes animate el).
   * If using CSS, sets the transform property. If not using CSS, sets the top / left property.
   *
   * @param value (int)
   *  - the animating property's value
   *
   * @param type (string) 'slider', 'reset', 'ticker'
   *  - the type of instance for which the function is being
   *
   * @param duration (int)
   *  - the amount of time (in ms) the transition should occupy
   *
   * @param params (array) optional
   *  - an optional parameter containing any variables that need to be passed in
   */
  var setPositionProperty = function(value, type, duration, params){
   // use CSS transform
   if(slider.usingCSS){
    // determine the translate3d value
    var propValue = slider.settings.mode == 'vertical' ? 'translate3d(0, ' + value + 'px, 0)' : 'translate3d(' + value + 'px, 0, 0)';
    // add the CSS transition-duration
    el.css('-' + slider.cssPrefix + '-transition-duration', duration / 1000 + 's');
    if(type == 'slide'){
     // set the property value
     el.css(slider.animProp, propValue);
     // bind a callback method - executes when CSS transition completes
     el.bind('transitionend webkitTransitionEnd oTransitionEnd MSTransitionEnd', function(){
      // unbind the callback
      el.unbind('transitionend webkitTransitionEnd oTransitionEnd MSTransitionEnd');
      updateAfterSlideTransition();
     });
    }else if(type == 'reset'){
     el.css(slider.animProp, propValue);
    }else if(type == 'ticker'){
     // make the transition use 'linear'
     el.css('-' + slider.cssPrefix + '-transition-timing-function', 'linear');
     el.css(slider.animProp, propValue);
     // bind a callback method - executes when CSS transition completes
     el.bind('transitionend webkitTransitionEnd oTransitionEnd MSTransitionEnd', function(){
      // unbind the callback
      el.unbind('transitionend webkitTransitionEnd oTransitionEnd MSTransitionEnd');
      // reset the position
      setPositionProperty(params['resetValue'], 'reset', 0);
      // start the loop again
      tickerLoop();
     });
    }
   // use JS animate
   }else{
    var animateObj = {};
    animateObj[slider.animProp] = value;
    if(type == 'slide'){
     el.animate(animateObj, duration, slider.settings.easing, function(){
      updateAfterSlideTransition();
     });
    }else if(type == 'reset'){
     el.css(slider.animProp, value)
    }else if(type == 'ticker'){
     el.animate(animateObj, speed, 'linear', function(){
      setPositionProperty(params['resetValue'], 'reset', 0);
      // run the recursive loop after animation
      tickerLoop();
     });
    }
   }
  }

  /**
   * Populates the pager with proper amount of pages
   */
  var populatePager = function(){
   var pagerHtml = '';
   var pagerQty = getPagerQty();
   // loop through each pager item
   for(var i=0; i < pagerQty; i++){
    var linkContent = '';
    // if a buildPager function is supplied, use it to get pager link value, else use index + 1
    if(slider.settings.buildPager && $.isFunction(slider.settings.buildPager)){
     linkContent = slider.settings.buildPager(i);
     slider.pagerEl.addClass('controlCustom');
    }else{
     linkContent = i + 1;
     slider.pagerEl.addClass('controlDefault');
    }
    // var linkContent = slider.settings.buildPager && $.isFunction(slider.settings.buildPager) ? slider.settings.buildPager(i) : i + 1;
    // add the markup to the string
    pagerHtml += '<div class="control"><a href="" data-slide-index="' + i + '" class="controlLink">' + linkContent + '</a></div>';
   };
   // populate the pager element with pager links
   slider.pagerEl.html(pagerHtml);
  }

  /**
   * Appends the pager to the controls element
   */
  var appendPager = function(){
   if(!slider.settings.pagerCustom){
    // create the pager DOM element
    slider.pagerEl = $('<div class="controlBox" />');
    // if a pager selector was supplied, populate it with the pager
    if(slider.settings.pagerSelector){
     $(slider.settings.pagerSelector).html(slider.pagerEl);
    // if no pager selector was supplied, add it after the wrapper
    }else{
     slider.controls.el.addClass('hasControl').append(slider.pagerEl);
    }
    // populate the pager
    populatePager();
   }else{
    slider.pagerEl = $(slider.settings.pagerCustom);
   }
   // assign the pager click binding
   slider.pagerEl.on('click', 'a', clickPagerBind);
  }

  /**
   * Appends prev / next controls to the controls element
   */
  var appendControls = function(){
   slider.controls.next = $('<a class="arrowNext" href="">' + slider.settings.nextText + '</a>');
   slider.controls.prev = $('<a class="arrowPrev" href="">' + slider.settings.prevText + '</a>');
   // bind click actions to the controls
   slider.controls.next.bind('click', clickNextBind);
   slider.controls.prev.bind('click', clickPrevBind);
   // if nextSlector was supplied, populate it
   if(slider.settings.nextSelector){
    $(slider.settings.nextSelector).append(slider.controls.next);
   }
   // if prevSlector was supplied, populate it
   if(slider.settings.prevSelector){
    $(slider.settings.prevSelector).append(slider.controls.prev);
   }
   // if no custom selectors were supplied
   if(!slider.settings.nextSelector && !slider.settings.prevSelector){
    // add the controls to the DOM
    slider.controls.directionEl = $('<div class="arrowBox" />');
    // add the control elements to the directionEl
    slider.controls.directionEl.append(slider.controls.prev).append(slider.controls.next);
    // slider.viewport.append(slider.controls.directionEl);
    slider.controls.el.addClass('hasArrowBox').append(slider.controls.directionEl);
   }
  }

  /**
   * Appends image captions to the DOM
   */
  var appendCaptions = function(){
   // cycle through each child
   slider.children.each(function(index){
    // get the image title attribute
    var title = $(this).find('img:first').attr('title');
    // append the caption
    if (title != undefined && ('' + title).length) {
                    $(this).append('<div class="slideTitle"><span>' + title + '</span></div>');
                }
   });
  }

  /**
   * Click next binding
   *
   * @param e (event)
   *  - DOM event object
   */
  var clickNextBind = function(e){
   // if auto show is running, stop it
   // if (slider.settings.auto) el.stopAuto();//上一图片时停止自动播放
   el.goToNextSlide();
   e.preventDefault();
  }

  /**
   * Click prev binding
   *
   * @param e (event)
   *  - DOM event object
   */
  var clickPrevBind = function(e){
   // if auto show is running, stop it
   // if (slider.settings.auto) el.stopAuto();//下一图片时停止自动播放
   el.goToPrevSlide();
   e.preventDefault();
  }

  /**
   * Click pager binding
   *
   * @param e (event)
   *  - DOM event object
   */
  var clickPagerBind = function(e){
   // if auto show is running, stop it
   // if (slider.settings.auto) el.stopAuto();//当按控制按钮时停止自动播放
   var pagerLink = $(e.currentTarget);
   if(pagerLink.attr('data-slide-index') !== undefined){
    var pagerIndex = parseInt(pagerLink.attr('data-slide-index'));
    // if clicked pager link is not active, continue with the goToSlide call
    if(pagerIndex != slider.active.index) el.goToSlide(pagerIndex);
    e.preventDefault();
   }
  }

  /**
   * Updates the pager links with an active class
   *
   * @param slideIndex (int)
   *  - index of slide to make active
   */
  var updatePagerActive = function(slideIndex){
   // if "short" pager type
   var len = slider.children.length; // nb of children
   if(slider.settings.pagerType == 'short'){
    if(slider.settings.maxSlides > 1) {
     len = Math.ceil(slider.children.length/slider.settings.maxSlides);
    }
    slider.pagerEl.html( (slideIndex + 1) + slider.settings.pagerShortSeparator + len);
    return;
   }
   // remove all pager active classes
   slider.pagerEl.find('a').removeClass('active');
   // apply the active class for all pagers
   slider.pagerEl.each(function(i, el) { $(el).find('a').eq(slideIndex).addClass('active'); });
  }

  /**
   * Performs needed actions after a slide transition
   */
  var updateAfterSlideTransition = function(){
   // if infinte loop is true
   if(slider.settings.infiniteLoop){
    var position = '';
    // first slide
    if(slider.active.index == 0){
     // set the new position
     position = slider.children.eq(0).position();
    // carousel, last slide
    }else if(slider.active.index == getPagerQty() - 1 && slider.carousel){
     position = slider.children.eq((getPagerQty() - 1) * getMoveBy()).position();
    // last slide
    }else if(slider.active.index == slider.children.length - 1){
     position = slider.children.eq(slider.children.length - 1).position();
    }
    if(position){
     if (slider.settings.mode == 'horizontal') { setPositionProperty(-position.left, 'reset', 0); }
     else if (slider.settings.mode == 'vertical') { setPositionProperty(-position.top, 'reset', 0); }
    }
   }
   // declare that the transition is complete
   slider.working = false;
   // onSlideAfter callback
   slider.settings.onSlideAfter(slider.children.eq(slider.active.index), slider.oldIndex, slider.active.index);
  }

  /**
   * Updates the direction controls (checks if either should be hidden)
   */
  var updateDirectionControls = function(){
   if(getPagerQty() == 1){
    slider.controls.prev.addClass('disabled');
    slider.controls.next.addClass('disabled');
   }else if(!slider.settings.infiniteLoop && slider.settings.hideControlOnEnd){
    // if first slide
    if (slider.active.index == 0){
     slider.controls.prev.addClass('disabled');
     slider.controls.next.removeClass('disabled');
    // if last slide
    }else if(slider.active.index == getPagerQty() - 1){
     slider.controls.next.addClass('disabled');
     slider.controls.prev.removeClass('disabled');
    // if any slide in the middle
    }else{
     slider.controls.prev.removeClass('disabled');
     slider.controls.next.removeClass('disabled');
    }
   }
  }

  /**
   * Initialzes the auto process
   */
  var initAuto = function(){
   // if autoDelay was supplied, launch the auto show using a setTimeout() call
   if(slider.settings.autoDelay > 0){
    var timeout = setTimeout(el.startAuto, slider.settings.autoDelay);
   // if autoDelay was not supplied, start the auto show normally
   }else{
    el.startAuto();
   }
   // if autoHover is requested
   if(slider.settings.autoHover){
    // on el hover
    el.hover(function(){
     // if the auto show is currently playing (has an active interval)
     if(slider.interval){
      // stop the auto show and pass true agument which will prevent control update
      el.stopAuto(true);
      // create a new autoPaused value which will be used by the relative "mouseout" event
      slider.autoPaused = true;
     }
    }, function(){
     // if the autoPaused value was created be the prior "mouseover" event
     if(slider.autoPaused){
      // start the auto show and pass true agument which will prevent control update
      el.startAuto(true);
      // reset the autoPaused value
      slider.autoPaused = null;
     }
    });
   }
  }

  /**
   * Initialzes the ticker process
   */
  var initTicker = function(){
   var startPosition = 0;
   // if autoDirection is "next", append a clone of the entire slider
   if(slider.settings.autoDirection == 'next'){
    el.append(slider.children.clone().addClass('bx-clone'));
   // if autoDirection is "prev", prepend a clone of the entire slider, and set the left position
   }else{
    el.prepend(slider.children.clone().addClass('bx-clone'));
    var position = slider.children.first().position();
    startPosition = slider.settings.mode == 'horizontal' ? -position.left : -position.top;
   }
   setPositionProperty(startPosition, 'reset', 0);
   // do not allow controls in ticker mode
   slider.settings.pager = false;
   slider.settings.controls = false;
   // if autoHover is requested
   if(slider.settings.tickerHover && !slider.usingCSS){
    // on el hover
    slider.viewport.hover(function(){
     el.stop();
    }, function(){
     // calculate the total width of children (used to calculate the speed ratio)
     var totalDimens = 0;
     slider.children.each(function(index){
       totalDimens += slider.settings.mode == 'horizontal' ? $(this).outerWidth(true) : $(this).outerHeight(true);
     });
     // calculate the speed ratio (used to determine the new speed to finish the paused animation)
     var ratio = slider.settings.speed / totalDimens;
     // determine which property to use
     var property = slider.settings.mode == 'horizontal' ? 'left' : 'top';
     // calculate the new speed
     var newSpeed = ratio * (totalDimens - (Math.abs(parseInt(el.css(property)))));
     tickerLoop(newSpeed);
    });
   }
   // start the ticker loop
   tickerLoop();
  }

  /**
   * Runs a continuous loop, news ticker-style
   */
  var tickerLoop = function(resumeSpeed){
   speed = resumeSpeed ? resumeSpeed : slider.settings.speed;
   var position = {left: 0, top: 0};
   var reset = {left: 0, top: 0};
   // if "next" animate left position to last child, then reset left to 0
   if(slider.settings.autoDirection == 'next'){
    position = el.find('.bx-clone').first().position();
   // if "prev" animate left position to 0, then reset left to first non-clone child
   }else{
    reset = slider.children.first().position();
   }
   var animateProperty = slider.settings.mode == 'horizontal' ? -position.left : -position.top;
   var resetValue = slider.settings.mode == 'horizontal' ? -reset.left : -reset.top;
   var params = {resetValue: resetValue};
   setPositionProperty(animateProperty, 'ticker', speed, params);
  }

  /**
   * Initializes touch events
   */
  var initTouch = function(){
   // initialize object to contain all touch values
   slider.touch = {
    start: {x: 0, y: 0},
    end: {x: 0, y: 0}
   }
   slider.viewport.bind('touchstart', onTouchStart);
  }

  /**
   * Event handler for "touchstart"
   *
   * @param e (event)
   *  - DOM event object
   */
  var onTouchStart = function(e){
   if(slider.working){
    e.preventDefault();
   }else{
    // record the original position when touch starts
    slider.touch.originalPos = el.position();
    var orig = e.originalEvent;
    // record the starting touch x, y coordinates
    slider.touch.start.x = orig.changedTouches[0].pageX;
    slider.touch.start.y = orig.changedTouches[0].pageY;
    // bind a "touchmove" event to the viewport
    slider.viewport.bind('touchmove', onTouchMove);
    // bind a "touchend" event to the viewport
    slider.viewport.bind('touchend', onTouchEnd);
   }
  }

  /**
   * Event handler for "touchmove"
   *
   * @param e (event)
   *  - DOM event object
   */
  var onTouchMove = function(e){
   var orig = e.originalEvent;
   // if scrolling on y axis, do not prevent default
   var xMovement = Math.abs(orig.changedTouches[0].pageX - slider.touch.start.x);
   var yMovement = Math.abs(orig.changedTouches[0].pageY - slider.touch.start.y);
   // x axis swipe
   if((xMovement * 3) > yMovement && slider.settings.preventDefaultSwipeX){
    e.preventDefault();
   // y axis swipe
   }else if((yMovement * 3) > xMovement && slider.settings.preventDefaultSwipeY){
    e.preventDefault();
   }
   if(slider.settings.mode != 'fade' && slider.settings.oneToOneTouch){
    var value = 0;
    // if horizontal, drag along x axis
    if(slider.settings.mode == 'horizontal'){
     var change = orig.changedTouches[0].pageX - slider.touch.start.x;
     value = slider.touch.originalPos.left + change;
    // if vertical, drag along y axis
    }else{
     var change = orig.changedTouches[0].pageY - slider.touch.start.y;
     value = slider.touch.originalPos.top + change;
    }
    setPositionProperty(value, 'reset', 0);
   }
  }

  /**
   * Event handler for "touchend"
   *
   * @param e (event)
   *  - DOM event object
   */
  var onTouchEnd = function(e){
   slider.viewport.unbind('touchmove', onTouchMove);
   var orig = e.originalEvent;
   var value = 0;
   // record end x, y positions
   slider.touch.end.x = orig.changedTouches[0].pageX;
   slider.touch.end.y = orig.changedTouches[0].pageY;
   // if fade mode, check if absolute x distance clears the threshold
   if(slider.settings.mode == 'fade'){
    var distance = Math.abs(slider.touch.start.x - slider.touch.end.x);
    if(distance >= slider.settings.swipeThreshold){
     slider.touch.start.x > slider.touch.end.x ? el.goToNextSlide() : el.goToPrevSlide();
     // el.stopAuto();//当触屏滑动图片时停止自动播放
    }
   // not fade mode
   }else{
    var distance = 0;
    // calculate distance and el's animate property
    if(slider.settings.mode == 'horizontal'){
     distance = slider.touch.end.x - slider.touch.start.x;
     value = slider.touch.originalPos.left;
    }else{
     distance = slider.touch.end.y - slider.touch.start.y;
     value = slider.touch.originalPos.top;
    }
    // if not infinite loop and first / last slide, do not attempt a slide transition
    if(!slider.settings.infiniteLoop && ((slider.active.index == 0 && distance > 0) || (slider.active.last && distance < 0))){
     setPositionProperty(value, 'reset', 200);
    }else{
     // check if distance clears threshold
     if(Math.abs(distance) >= slider.settings.swipeThreshold){
      distance < 0 ? el.goToNextSlide() : el.goToPrevSlide();
      // el.stopAuto();//当触屏滑动图片时停止自动播放
     }else{
      // el.animate(property, 200);
      setPositionProperty(value, 'reset', 200);
     }
    }
   }
   slider.viewport.unbind('touchend', onTouchEnd);
  }

  /**
   * Window resize event callback
   */
  var resizeWindow = function(e){
   // don't do anything if slider isn't initialized.
   if(!slider.initialized) return;
   // get the new window dimens (again, thank you IE)
   var windowWidthNew = $(window).width();
   var windowHeightNew = $(window).height();
   // make sure that it is a true window resize
   // *we must check this because our dinosaur friend IE fires a window resize event when certain DOM elements
   // are resized. Can you just die already?*
   if(windowWidth != windowWidthNew || windowHeight != windowHeightNew){
    // set the new window dimens
    windowWidth = windowWidthNew;
    windowHeight = windowHeightNew;
    // update all dynamic elements
    el.redrawSlider();
    // Call user resize handler
    slider.settings.onSliderResize.call(el, slider.active.index);
   }
  }

  /**
   * ===================================================================================
   * = PUBLIC FUNCTIONS
   * ===================================================================================
   */

  /**
   * Performs slide transition to the specified slide
   *
   * @param slideIndex (int)
   *  - the destination slide's index (zero-based)
   *
   * @param direction (string)
   *  - INTERNAL USE ONLY - the direction of travel ("prev" / "next")
   */
  el.goToSlide = function(slideIndex, direction){
   // if plugin is currently in motion, ignore request
   if(slider.working || slider.active.index == slideIndex) return;
   // declare that plugin is in motion
   slider.working = true;
   // store the old index
   slider.oldIndex = slider.active.index;
   // if slideIndex is less than zero, set active index to last child (this happens during infinite loop)
   if(slideIndex < 0){
    slider.active.index = getPagerQty() - 1;
   // if slideIndex is greater than children length, set active index to 0 (this happens during infinite loop)
   }else if(slideIndex >= getPagerQty()){
    slider.active.index = 0;
   // set active index to requested slide
   }else{
    slider.active.index = slideIndex;
   }
   // onSlideBefore, onSlideNext, onSlidePrev callbacks
   slider.settings.onSlideBefore(slider.children.eq(slider.active.index), slider.oldIndex, slider.active.index);
   if(direction == 'next'){
    slider.settings.onSlideNext(slider.children.eq(slider.active.index), slider.oldIndex, slider.active.index);
   }else if(direction == 'prev'){
    slider.settings.onSlidePrev(slider.children.eq(slider.active.index), slider.oldIndex, slider.active.index);
   }
   // check if last slide
   slider.active.last = slider.active.index >= getPagerQty() - 1;
   // update the pager with active class
   if(slider.settings.pager) updatePagerActive(slider.active.index);
   // // check for direction control update
   if(slider.settings.controls) updateDirectionControls();
   // if slider is set to mode: "fade"
   if(slider.settings.mode == 'fade'){
    // if adaptiveHeight is true and next height is different from current height, animate to the new height
    if(slider.settings.adaptiveHeight && slider.viewport.height() != getViewportHeight()){
     slider.viewport.animate({height: getViewportHeight()}, slider.settings.adaptiveHeightSpeed);
    }
    // fade out the visible child and reset its z-index value
    slider.children.filter(':visible').fadeOut(slider.settings.speed).css({zIndex: 0});
    // fade in the newly requested slide
    slider.children.eq(slider.active.index).css('zIndex', slider.settings.slideZIndex+1).fadeIn(slider.settings.speed, function(){
     $(this).css('zIndex', slider.settings.slideZIndex);
     updateAfterSlideTransition();
    });
   // slider mode is not "fade"
   }else{
    // if adaptiveHeight is true and next height is different from current height, animate to the new height
    if(slider.settings.adaptiveHeight && slider.viewport.height() != getViewportHeight()){
     slider.viewport.animate({height: getViewportHeight()}, slider.settings.adaptiveHeightSpeed);
    }
    var moveBy = 0;
    var position = {left: 0, top: 0};
    // if carousel and not infinite loop
    if(!slider.settings.infiniteLoop && slider.carousel && slider.active.last){
     if(slider.settings.mode == 'horizontal'){
      // get the last child position
      var lastChild = slider.children.eq(slider.children.length - 1);
      position = lastChild.position();
      // calculate the position of the last slide
      moveBy = slider.viewport.width() - lastChild.outerWidth();
     }else{
      // get last showing index position
      var lastShowingIndex = slider.children.length - slider.settings.minSlides;
      position = slider.children.eq(lastShowingIndex).position();
     }
     // horizontal carousel, going previous while on first slide (infiniteLoop mode)
    }else if(slider.carousel && slider.active.last && direction == 'prev'){
     // get the last child position
     var eq = slider.settings.moveSlides == 1 ? slider.settings.maxSlides - getMoveBy() : ((getPagerQty() - 1) * getMoveBy()) - (slider.children.length - slider.settings.maxSlides);
     var lastChild = el.children('.bx-clone').eq(eq);
     position = lastChild.position();
    // if infinite loop and "Next" is clicked on the last slide
    }else if(direction == 'next' && slider.active.index == 0){
     // get the last clone position
     position = el.find('> .bx-clone').eq(slider.settings.maxSlides).position();
     slider.active.last = false;
    // normal non-zero requests
    }else if(slideIndex >= 0){
     var requestEl = slideIndex * getMoveBy();
     position = slider.children.eq(requestEl).position();
    }

    /* If the position doesn't exist
     * (e.g. if you destroy the slider on a next click),
     * it doesn't throw an error.
     */
    if ("undefined" !== typeof(position)) {
     var value = slider.settings.mode == 'horizontal' ? -(position.left - moveBy) : -position.top;
     // plugin values to be animated
     setPositionProperty(value, 'slide', slider.settings.speed);
    }
   }
  }

  /**
   * Transitions to the next slide in the show
   */
  el.goToNextSlide = function(){
   // if infiniteLoop is false and last page is showing, disregard call
   if (!slider.settings.infiniteLoop && slider.active.last) return;
   var pagerIndex = parseInt(slider.active.index) + 1;
   el.goToSlide(pagerIndex, 'next');
  }

  /**
   * Transitions to the prev slide in the show
   */
  el.goToPrevSlide = function(){
   // if infiniteLoop is false and last page is showing, disregard call
   if (!slider.settings.infiniteLoop && slider.active.index == 0) return;
   var pagerIndex = parseInt(slider.active.index) - 1;
   el.goToSlide(pagerIndex, 'prev');
  }

  /**
   * Starts the auto show
   *
   * @param preventControlUpdate (boolean)
   *  - if true, auto controls state will not be updated
   */
  el.startAuto = function(preventControlUpdate){
   // if an interval already exists, disregard call
   if(slider.interval) return;
   // create an interval
   slider.interval = setInterval(function(){
    slider.settings.autoDirection == 'next' ? el.goToNextSlide() : el.goToPrevSlide();
   }, slider.settings.pause);
   // if auto controls are displayed and preventControlUpdate is not true
   if (slider.settings.autoControls && preventControlUpdate != true) updateAutoControls('stop');
  }

  /**
   * Stops the auto show
   *
   * @param preventControlUpdate (boolean)
   *  - if true, auto controls state will not be updated
   */
  el.stopAuto = function(preventControlUpdate){
   // if no interval exists, disregard call
   if(!slider.interval) return;
   // clear the interval
   clearInterval(slider.interval);
   slider.interval = null;
   // if auto controls are displayed and preventControlUpdate is not true
   if (slider.settings.autoControls && preventControlUpdate != true) updateAutoControls('start');
  }

  /**
   * Returns current slide index (zero-based)
   */
  el.getCurrentSlide = function(){
   return slider.active.index;
  }

  /**
   * Returns current slide element
   */
  el.getCurrentSlideElement = function(){
   return slider.children.eq(slider.active.index);
  }

  /**
   * Returns number of slides in show
   */
  el.getSlideCount = function(){
   return slider.children.length;
  }

  /**
   * Update all dynamic slider elements
   */
  el.redrawSlider = function(){
   // resize all children in ratio to new screen size
   slider.children.add(el.find('.bx-clone')).width(getSlideWidth());
   // adjust the height
   slider.viewport.css('height', getViewportHeight());
   // update the slide position
   if(!slider.settings.ticker) setSlidePosition();
   // if active.last was true before the screen resize, we want
   // to keep it last no matter what screen size we end on
   if (slider.active.last) slider.active.index = getPagerQty() - 1;
   // if the active index (page) no longer exists due to the resize, simply set the index as last
   if (slider.active.index >= getPagerQty()) slider.active.last = true;
   // if a pager is being displayed and a custom pager is not being used, update it
   if(slider.settings.pager && !slider.settings.pagerCustom){
    populatePager();
    updatePagerActive(slider.active.index);
   }
  }

  /**
   * Destroy the current instance of the slider (revert everything back to original state)
   */
  el.destroySlider = function(){
   // don't do anything if slider has already been destroyed
   if(!slider.initialized) return;
   slider.initialized = false;
   $('.bx-clone', this).remove();
   slider.children.each(function() {
    $(this).data("origStyle") != undefined ? $(this).attr("style", $(this).data("origStyle")) : $(this).removeAttr('style');
   });
   $(this).data("origStyle") != undefined ? this.attr("style", $(this).data("origStyle")) : $(this).removeAttr('style');
   $(this).unwrap().unwrap();
   if(slider.controls.el) slider.controls.el.remove();
   if(slider.controls.next) slider.controls.next.remove();
   if(slider.controls.prev) slider.controls.prev.remove();
   if(slider.pagerEl && slider.settings.controls) slider.pagerEl.remove();
   $('.slideTitle', this).remove();
   if(slider.controls.autoEl) slider.controls.autoEl.remove();
   clearInterval(slider.interval);
   if(slider.settings.responsive) $(window).unbind('resize', resizeWindow);
  }

  /**
   * Reload the slider (revert all DOM changes, and re-initialize)
   */
  el.reloadSlider = function(settings){
   if (settings != undefined) options = settings;
   el.destroySlider();
   init();
  }

  init();

  // returns the current jQuery object
  return this;
 }

})(jQuery);
